1. Field
This disclosure relates generally to apparatus for testing semiconductor wafers, and more specifically to a system, method and apparatus for coupling a universal test interface with a probe card system for testing with a wafer prober.
2. Related Art
In a wafer prober, a probe card is an interface between an electronic test system and a semiconductor wafer. The purpose of the probe card is to provide an electrical path between the test system and the circuits on the wafer, thereby permitting testing and validation of the circuits. Testing is typically done before the circuits are diced and packaged.
During development of a probe card, cables are manually connected to and/or removed from any of several access test points on the probe card. The probes of the probe card are connected to a test head. The cost of a test head of a probe card can be on the order of $10,000-$50,000 or more. Manually connecting cables can be time consuming and cumbersome. Additionally, manual connecting of cables can result in irreversible damage to the sensitive probes of the very expensive test head.
Hundreds or even thousands of access point are desirable in testing. It would be desirable to have a universal interface for connecting possibly thousands of pins simultaneously to an electrical interface of the probe card. These thousands of pins can be connected to electrical cables in order to transmit signals to and from the wafer prober machine to the semiconductor wafer. However, the force required to plug thousands of pins of a test pad into the thousands of holes of the electrode pad of a probe card can take hundreds of pounds of force. If the test head of the probe card is in contact with the wafer, the hundreds of pounds of force could easily damage the fragile probes of the test head.